Bring on the Sentiment

More than $16 million will be spent, and some four billion people around the world will watch. Here’s how the young couple will pull it off.

There will be one glaring absence on the big day: the mother of the groom, whom William has called “quite simply, the best mum in the world.” So it was fitting (and poignant) when Wills proposed to Kate with his mom’s 18-carat sapphire-and-diamond engagement ring.

Keep the Plans a Secret

Everyone loves surprises, right? The Brits are mad for Kate’s fashion sense. So much so that the royal blue dress the five-foot-ten, size-two beauty wore to announce her engagement–made by Issa, one of her favorite designers–sold out on net-a-porter.com within 24 hours. But the bride has kept mum about her wedding gown.

But Spill Some Details

Before the official press conference, Will and Kate’s engagement was announced online, followed by news that the happy couple would be married at Westminster Abbey by the archbishop of Canterbury and that the Queen would throw a traditional reception at Buckingham Palace. But that was enough tradition for the modern couple. The real party will be a private dinner and dance for close friends and family only.

Don’t Look Greedy

Royal aides say the couple is asking that guests donate to charity in lieu of sending presents because those bestowed on royals in the past can be, well, a bit impractical. When the Queen Mum and George VI were married in 1923, they were given 1,000 gold-eyed needles.

Arrive (Or at Least Depart) in Style

Kate has said she’d prefer to make her way to the ceremony by car rather than in the traditional, Cinderellaesque “glass coach,” though she will depart by carriage. One possible reason besides thrift? She’s allergic to horses.

Do a Few Dry Runs First

Two rehearsal carriage rides will take place before the big day, the first for pacing and the second–in the dead of night–with the actual royal carriages carrying people of exactly the same weight as the wedding party. Then coachmen will adjust the springs so that the carriage “doesn’t sway too much and make the passengers sick,” says a former driver.

Keep Security Tight

All trash bins along the route will be sealed ahead of time to prevent anyone from hiding a bomb inside them. On the wedding day itself, all rooftops will be covered by police to foil potential snipers. Kate will be followed “from the moment she gets up in the morning,” says Alex Bomberg, a former royal aide. While the royal family will pay for the wedding itself, the security, paid for by the public, is estimated to cost at least $8 million.

Don’t Forget Souvenirs

The wedding will likely generate some $1 billion in revenue. And a chunk of that will come from the mugs emblazoned with the couple’s likeness, as well as unauthorized items such as tea towels–and even condoms.